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Individual Analysis Of T2*-Weighted Gradient Echo Imaging In Asymptomatic And Symptomatic Athletes, Xianglun Mao
Individual Analysis Of T2*-Weighted Gradient Echo Imaging In Asymptomatic And Symptomatic Athletes, Xianglun Mao
Open Access Theses
Mild traumatic brain injury (mTBI), is a commonly occurred sports-related injury, especially in contact sports like football and soccer. Hemorrhage will appear as hypointense lesions on T2 *-weighted images, resulting from mTBI. Thus, T 2*-weighted gradient echo pulse sequence can be used to generate magnitude susceptibility-weighted (SW) images, and to further detect negative intensity changes of different regions of interests (ROIs) inside human brains. Our goal was to investigate how the ROI-specific intensity changes in each individual sports athlete over a single competition season and to interrogate whether these changes are correlated with repetitive subconcussive or …
Computational Study Of Nano- And Meso-Scale Size Effects On Thermal Transport, Eshaan Mathew
Computational Study Of Nano- And Meso-Scale Size Effects On Thermal Transport, Eshaan Mathew
Open Access Theses
In the era where structures and devices are of the order of a few nanometers, a detailed understanding on the heat carriers in nanostructured devices is required to enable further improvements and advances. ^ In the first portion of this thesis we develop a new methodology using Molecular Dynamics (MD) to determine the thermal conductivity of argon with a modified Leonard Jones potential as a function of the modulation frequency input heat flux. We observe a decrease in the thermal conductivity as the heat transport enters the ballistic regime by an order of magnitude which agrees with some of the …
Quantifying Moisture Transport In Cementitious Materials Using Neutron Radiography, Catherine L. Lucero
Quantifying Moisture Transport In Cementitious Materials Using Neutron Radiography, Catherine L. Lucero
Open Access Theses
A portion of the concrete pavements in the US have recently been observed to have premature joint deterioration. This damage is caused in part by the ingress of fluids, like water, salt water, or deicing salts. The ingress of these fluids can damage concrete when they freeze and expand or can react with the cementitious matrix causing damage. To determine the quality of concrete for assessing potential service life it is often necessary to measure the rate of fluid ingress, or sorptivity. Neutron imaging is a powerful method for quantifying fluid penetration since it can describe where water has penetrated, …
Measurement, Characterization, And Effects Of Head Impacts In Women's Soccer, Emily C. Mccuen
Measurement, Characterization, And Effects Of Head Impacts In Women's Soccer, Emily C. Mccuen
Open Access Theses
The potential for long term neurological deficits resulting from repetitive head trauma is a major concern for collision sport athletes. Research conducted on football played has found neurophysiologic changes in the absence of concussion in athletes as early as high school age. Given that female soccer players show the highest rate of concussion for female athletes and a higher rate of concussion than their male counterparts, it is important to characterize the types of impacts female soccer athletes receive and assess female soccer athletes for neurophysiologic changes due to these impacts. This work paired head impact sensors with functional MRI …
Smart V-Belt, Kyle J. Mosier
Smart V-Belt, Kyle J. Mosier
Open Access Theses
The purpose of this research was to develop a method for detecting premature failure in a v-belt using capacitance and resistance readings. Another goal of the research was to detect tension values on the belt using the same readings. Materials of current belts and possible materials for a prototype belt were tested. Materials were chosen, and prototype belts were built. Pulley system configurations were developed and built. Sections of the belt designs were tested for capacitance and resistance before and after various methods of damage. Capacitance was chosen as the better sensing method. Certain layered belt configurations and sheave configurations …
The Effect Of Integrated Science, Engineering, Technology, And Mathematics Lessons On Interest And Engagement Of Secondary Students, Cameron Nunan
The Effect Of Integrated Science, Engineering, Technology, And Mathematics Lessons On Interest And Engagement Of Secondary Students, Cameron Nunan
Open Access Theses
This study set out to answer the research question: Does teaching a single lesson, utilizing the interconnected principles of STEM in STEM courses, increase overall student interest and engagement in STEM classes in secondary schools? The literature review established a need for student interest in STEM to help fill future STEM careers. ^ Integrated STEM lessons were a viable option for increasing interest, but existing research on the matter was limited. Integrated STEM lessons were applied at a test site school using a multiple baseline framework and evaluated responses with a variation of the Intrinsic Motivation Inventory (IMI). According to …
Flexible Weapons Architecture Design, William C. Pyant
Flexible Weapons Architecture Design, William C. Pyant
Open Access Theses
Present day air-delivered weapons are of a closed architecture, with little to no ability to tailor the weapon for the individual engagement. The closed architectures require weaponeers to make the target fit the weapon instead of fitting the individual weapons to a target. The concept of a flexible weapons aims to modularize weapons design using an open architecture shell into which different modules are inserted to achieve the desired target fractional damage while reducing cost and civilian casualties. This thesis shows that the architecture design factors of damage mechanism, fusing, weapons weight, guidance, and propulsion are significant in enhancing weapon …
Exploiting Intra-Warp Address Monotonicity For Fast Memory Coalescing In Gpus, Hector Rodriguez-Simmonds
Exploiting Intra-Warp Address Monotonicity For Fast Memory Coalescing In Gpus, Hector Rodriguez-Simmonds
Open Access Theses
Graphics Processing Units (GPUs) are growing increasingly popular as general purpose compute accelerators. GPUs are best suited for applications which have abundant data parallelism wherein the computation expressed as a single thread can be applied over a large set of data items. One key constraint that affects application performance on GPUs is that the underlying hardware is single-instruction, multiple data (SIMD) hardware which requires parallel instructions from the multiple threads to execute in a lock-step manner. The benefits of lock-step execution can be seriously degraded if the threads diverge (because of memory or branches). Specifically in the case of memory, …
Preparation Of Bismuth Telluride Based Thermoelectric Nanomaterials Via Low-Energy Ball Milling And Their Property Characterizations, Christopher Robinson
Preparation Of Bismuth Telluride Based Thermoelectric Nanomaterials Via Low-Energy Ball Milling And Their Property Characterizations, Christopher Robinson
Open Access Theses
Thermoelectric materials are able to convert energy between heat and electricity with no moving parts, making them very appealing for power generation purposes. This is particularly appealing since many forms of energy generation lose energy to waste heat. The Livermore National Laboratory estimates that up to 55% of the energy created in traditional power plants is lost through heat generation [1]. As greenhouse gas emissions become a more important issue, large sources of waste like this will need to be harnessed. ^ Adoption of these materials has been limited due to the cost and efficiency of current technology. Bismuth telluride …
Spectral Broadening Of Frequency Combs Via Pulse Apodization Prior To Nonlinear Propagation, Oscar E. Sandoval
Spectral Broadening Of Frequency Combs Via Pulse Apodization Prior To Nonlinear Propagation, Oscar E. Sandoval
Open Access Theses
This thesis focuses on specific methods for spectrally broadening large repetition rate frequency combs using the idea that tailoring the shape of the seed pulse prior to nonlinear propagation will result in a spectrally flatter comb. A spectrally flat comb is desired for applications in optical communications, arbitrary waveform generation, and microwave photonic filtering. Three experimental setups using Fourier transform pulse shapers, Dispersion Decreasing Fiber (DDF) or Highly Nonlinear Fiber (HNLF) as the nonlinear propagation media were performed. Simulations employing the Split Step Fourier Method to solve the Nonlinear Schrödinger Equation were performed to analyze the experimental results. The first …
Examining Unawareness Of Construction Law Principles From A Small Contractor's Perspective, Ketaki Shiralkar
Examining Unawareness Of Construction Law Principles From A Small Contractor's Perspective, Ketaki Shiralkar
Open Access Theses
Construction industry encompasses myriads of small trades within itself. If we take a microscope and observe, what looks from outside as one big single unit, is in fact made up of many small cogs of a wheel, important ones though, as without them, the functionality of the industry wouldn't be proper. As much as the existence of these small scale contractor's companies is important, so is their survival. There have been many reasons as to why contractors fail, but this study is limited to focus on one of them, which is, the absence of legal knowledge among employees of a …
Numerical Simulation And Characterization Of Jet Flows In Indoor Environments, Zhu Shi
Numerical Simulation And Characterization Of Jet Flows In Indoor Environments, Zhu Shi
Open Access Theses
Jet flows are prevalent in indoor environment and other engineering applications. Typical examples in indoor environment include the flow discharged from personal ventilation systems, and the jet exhaled through breathing or coughing. When there is density (or temperature) difference between the jet and surroundings, jet flow becomes stratified jet. Due to its complication, stratified jet flow is difficult to model, especially in the developing or transitional region of the flow. Studying stratified jet flows is of great significance for understanding the mixing dynamics of jet and ambient environment. This is particularly important for optimizing indoor environment design, or obtaining accurate …
Machining As A Mechanical Property Test Revisited, David L. Smith
Machining As A Mechanical Property Test Revisited, David L. Smith
Open Access Theses
There is much need for data on mechanical behavior of metals at high strains and strain rates. This need is dictated by modeling of processes like forming and machining, wherein the material in the deformation zone is subjected to severe deformation conditions atypical of conventional material property tests such as tension and torsion. Accurate flow stress data is an essential input for robust prediction of process outputs. Similar requirements arise from applications in high speed ballistic penetration and design of materials for armor. Since the deformation zone in cutting of metals is characterized by unique and extreme combinations of strain, …
Failure Analysis Of High Performance Ballistic Fibers, Jennifer S. Spatola
Failure Analysis Of High Performance Ballistic Fibers, Jennifer S. Spatola
Open Access Theses
High performance fibers have a high tensile strength and modulus, good wear resistance, and a low density, making them ideal for applications in ballistic impact resistance, such as body armor. However, the observed ballistic performance of these fibers is much lower than the predicted values. Since the predictions assume only tensile stress failure, it is safe to assume that the stress state is affecting fiber performance. The purpose of this research was to determine if there are failure mode changes in the fiber fracture when transversely loaded by indenters of different shapes. An experimental design mimicking transverse impact was used …
Ads-B Used In Improvement Of Air Traffic Control, Hao Wang
Ads-B Used In Improvement Of Air Traffic Control, Hao Wang
Open Access Theses
Automatic dependent surveillance – broadcast (ADS-B) is a central component of the NextGen air traffic control program. This surveillance technology can replace current secondary surveillance radars (SSR) and improve cockpit situational awareness. The service can improve traffic surveillance capabilities by sharing accurate aircraft position information between pilots and air traffic controllers. In addition, ADS-B provides pilots with weather as well as air traffic information for nearby area. In order to receive these traffic and weather services, a pilot must have appropriate onboard equipment including GPS receiver, Universal Access Transceiver, antenna and multi-function cockpit display which is capable of receiving and …
An Experimental Investigation Of A Premixed Laminar Flame Using Tunable Diode Laser And Quantitative Imaging Of Radiation Intensity, Weichao Wang
Open Access Theses
Simultaneous CO concentration and temperature measurements using Tunable Diode Laser Absorption Spectroscopy (TDLAS) are reported in this study. Ro-vibrational transitions of CO, R(27) and R(6) are used for probing absorbance profiles. Premixed ethylene-air flat flame on a McKenna burner is used for creating combustion gaseous products at equivalence ratio 0.83 to 1.82. Nitrogen shroud flow is used for preventing air mixing. Both Direction Absorption (DA) and Wavelength Modulation Spectroscopy (WMS) experiments are conducted. Experimental results are compared with literature and simulation using CHEMKIN and chemical equilibrium. Reasonable agreements are achieved between experiment and simulation. The CO detection limit is determined …
Recursive Tree Traversal Dependence Analysis, Yusheng Weijiang
Recursive Tree Traversal Dependence Analysis, Yusheng Weijiang
Open Access Theses
While there has been much work done on analyzing and transforming regular programs that operate over linear arrays and dense matrices, comparatively little has been done to try to carry these optimizations over to programs that operate over heap-based data structures using pointers. Previous work has shown that point blocking, a technique similar to loop tiling in regular programs, can help increase the temporal locality of repeated tree traversals. Point blocking, however, has only been shown to work on tree traversals where each traversal is fully independent and would allow parallelization, greatly limiting the types of applications that this transformation …
Magnetic Manipulation And Multimodal Imaging For Single Cell Direct Mechanosensing, Robert L. Wilson
Magnetic Manipulation And Multimodal Imaging For Single Cell Direct Mechanosensing, Robert L. Wilson
Open Access Theses
The study of internal mechanics of single cells is paramount to understand mechanisms of mechanoregulation. External loading and cell-mediated force generation result in changes in cell shape, rheology, and the deformation of subcellular structures such as the nucleus. Moreover, alterations in the processes that regulate these responses have been further correlated to specific pathologies. Cellular deformation is often studied through application of forces in the environment of the cell, relying on strain and stress transfer through focal adhesions and the cytoskeletal system. However, the transfer of these external forces to internal mechanics can introduce uncertainties in the interpretation of subcellular …
Investigation Of Industry Perceptions Of Building Information Modeling (Bim)-Based Estimating Practices In The U.S. And China, Zhihang Yi
Open Access Theses
While the Building Information Modeling (BIM) technology has been seen as next revolutionary technology for the Architectural, Engineering, Construction and Facility Management (AEC/FM) fields, the AEC/FM industry does not implement BIM technology on the cost estimating practices as widely as expected. The efficiency improvement on cost estimating with BIM could be accomplished through automating quantity take-offs, closely collaborating design with the estimating professionals and so on. This research explores the advantages and barriers of imbedding BIM technology into the estimating practices which enables the industry deepen their understandings on BIM-based cost estimation method. This study also compares the industry perceptions …
Linear Matrix Inequality-Based Nonlinear Adaptive Robust Control With Application To Unmanned Aircraft Systems, David William Kun
Linear Matrix Inequality-Based Nonlinear Adaptive Robust Control With Application To Unmanned Aircraft Systems, David William Kun
Open Access Theses
Unmanned aircraft systems (UASs) are gaining popularity in civil and commercial applications as their lightweight on-board computers become more powerful and affordable, their power storage devices improve, and the Federal Aviation Administration addresses the legal and safety concerns of integrating UASs in the national airspace. Consequently, many researchers are pursuing novel methods to control UASs in order to improve their capabilities, dependability, and safety assurance. The nonlinear control approach is a common choice as it offers several benefits for these highly nonlinear aerospace systems (e.g., the quadrotor). First, the controller design is physically intuitive and is derived from well known …
Real-Time Rss-Based Indoor Navigation For Autonomous Uav Flight, Sangjun Lee
Real-Time Rss-Based Indoor Navigation For Autonomous Uav Flight, Sangjun Lee
Open Access Theses
Navigation for the autonomous flight of Unmanned Aerial Vehicles (UAVs) in an indoor space has attracted much attention recently. One of the main goals of an indoor navigation system is developing an alternative method to obtain position information that can replace or complement the global positioning system. While much research has focused on vision-based indoor navigation systems, this paper aims to develop a Received Signal Strength (RSS)-based navigation system, which is a more cost effective alternative. Then, the position and attitude of a UAV can be computed by the fusion of RSS measurements and measurements from the onboard inertial measurement …
Dielectric Coating Of Iron Particles By Electrostatic Colloidal Deposition, Daniel Kim
Dielectric Coating Of Iron Particles By Electrostatic Colloidal Deposition, Daniel Kim
Open Access Theses
Iron is a soft magnetic material widely used in electric motors, generators, and transformers because they demand high permeability and low core loss. The main goal of this project is to develop a commercially viable coating of iron powders for press-and-sinter processing that would enable higher firing temperatures to anneal out magnetic defects, while maintaining high electrical resistivity (∼10,000 μΩ-cm) and high iron density (>90 %). An alumina-modified colloidal silica (LUDOX CL), was used in early work to make Fe (-)/SiO2 (+) in a wet-pressed route. The highest relative density and resistivity measurements for a wet-pressing route were …
Optimizing Electrode Thickness And Material For Laser-Induced Electrothermal Flow, Jian Wei Khor
Optimizing Electrode Thickness And Material For Laser-Induced Electrothermal Flow, Jian Wei Khor
Open Access Theses
In this article, the material dependence of electrothermal flow is studied to optimize an optoelectric particle manipulation technique called Rapid Electrokinetic Patterning (REP). REP utilizes a heat source to produce temperature gradients, which, in this study, are induced by the application of a 1064 nm cw laser. The simultaneous application of an uniform AC electric field assemble colloids on the surface of an electrode that can be moved by translating the laser. The temperature gradients produced from the heat source are crucial in REP as the higher the temperature gradient the faster the electrothermal flow. Thus, optimization of temperature gradients …
A Probabilistic Model Of Benefit-Cost Analysis For Highway Construction Projects, Yue He
A Probabilistic Model Of Benefit-Cost Analysis For Highway Construction Projects, Yue He
Open Access Theses
Deterministic method occupies the predominant position in economic analysis. However, by using a single value to estimate the project value, deterministic method would hide the risk under it. Analysts may make incorrect judgments by looking at a value without knowing the likelihood of its occurrence and the consequences of its occurrence. A probabilistic model was developed in this study to address this problem. It was found in this study that the traffic flows on Indiana highways follow logistic distributions rather than normal distributions as generally believed. The application of the probabilistic model was illustrated through a case study. The results …
Air Traffic Management Under Uncertain Weather Impact, Le Gao
Air Traffic Management Under Uncertain Weather Impact, Le Gao
Open Access Theses
Air traffic management under uncertain weather impact is a difficult problem. In this thesis, by dividing the whole air traffic systems into small cells, a new method using database to integrate weather and flight data is proposed. An algorithm has been developed to project weather data onto cells. This research also uses a predictive view to find ights which are affected by severe weather. And a prototype detour algorithm is applied on those flights based on the status information of each cell.
Improving Product Design Phase For Engineer To Order (Eto) Product With Knowledge Base Engineering (Kbe), Hanhdung Thi Dinh
Improving Product Design Phase For Engineer To Order (Eto) Product With Knowledge Base Engineering (Kbe), Hanhdung Thi Dinh
Open Access Theses
In industry currently Computer Aided Design (CAD) is an important tool for the modification, analysis, or optimization of the 3D virtual environment that replicates the physical product. CAD software is an efficient and reliable tool. However, as globalization increases customer demands, this process needs to be faster and more efficient to accommodate changing product design situations, especially for Engineer-to- Order (ETO) products. ^ The traditional method of product design process is to operate CAD software without argumentation. Design engineers create CAD prototypes and drawings based on available knowledge and information which comes from engineering experts, company standards, industrial practices as …
The Effect Of Maximum Aggregate Size On The Shear Strength Of Geometrically Scaled Reinforced Concrete Beams, Derek Robert Daluga
The Effect Of Maximum Aggregate Size On The Shear Strength Of Geometrically Scaled Reinforced Concrete Beams, Derek Robert Daluga
Open Access Theses
Shear strength of reinforced concrete beams without web reinforcement has been reported to decrease with increases in depth. This is often referred to as a size effect. This reduction in shear strength has been reported to decrease with the use of web reinforcement and increases in maximum aggregate size. ^ The purpose of this study was to test two hypotheses 1) shear strength increases with increases in maximum aggregate size and 2) aggregate gradation affects this increase in shear strength. Maximum aggregate size is defined here as the size of the smallest sieve opening through which all aggregate particles pass. …
Considerations For Nondestructive Evaluation Of Discontinuous Fiber Composites Using Dynamic Analysis, Rebecca A. Cutting
Considerations For Nondestructive Evaluation Of Discontinuous Fiber Composites Using Dynamic Analysis, Rebecca A. Cutting
Open Access Theses
Knowledge of the composite microstructure is vital to predicting performance of the structural member. However, depending on the manufacturing process, the microstructure of the part may be unknown and not predictable with simulation software. A few non-destructive evaluation techniques have been adjusted to predict fiber orientation of composites, including CT scans and thermography, but none have proven acceptable on a large scale with the amount of fidelity required. This research investigated the use of dynamic analysis as a non-destructive evaluation technique to predict fiber orientation of discontinuous fiber compression molded parts. While the method is currently unable to predict individual …
Effect Of Electrode Geometry On High Energy Spark Discharges In Air, Mounia Belmouss
Effect Of Electrode Geometry On High Energy Spark Discharges In Air, Mounia Belmouss
Open Access Theses
The government, aerospace, and transportation industries are deeply invested in developing new technologies to improve the performance and maneuverability of current and future aircraft while reducing aerodynamic noise and environmental impact. One of the key pathways to meet these goals is through aerodynamic flow control, which can involve suppressing or inducing separation, transition and management of turbulence in boundary layers, increasing the lift and reducing the drag of airfoils, and gas mixing to control fluctuating forces and aerodynamic noise [1]. In this dissertation, the complex flow field following a spark discharge is studied for a range of geometries and discharge …
Low Income, Supermarket Accessibility, And The Transportation Network: A Multimodal Analysis Identifying Areas Of Poor Accessibility And Intervention Strategies In Indianapolis, Indiana, Andrea Leigh Bailey
Low Income, Supermarket Accessibility, And The Transportation Network: A Multimodal Analysis Identifying Areas Of Poor Accessibility And Intervention Strategies In Indianapolis, Indiana, Andrea Leigh Bailey
Open Access Theses
The United States Department of Agriculture (USDA) Economic Research Service estimates that 23.5 million people live in food deserts, over half of which are considered low-income residents. Accurately defining a food desert is crucial as the designated areas can benefit from grant opportunities and funding priority. To qualify as an urban food desert, the USDA requires that at least 500 residents or one-third of the population live outside a one-mile buffer from a supermarket as well as have a median income of less than 80% of the area average or a poverty rate of greater than 20%. Approaches in the …